The alert was issued by the UC Berkeley Seismological Laboratory’s ShakeAlert earthquake early-warning project. The demonstration warning system provided 10 seconds warning (as shown in the video above) at laboratories in Berkeley, San Francisco, Oakland and San Jose. It preceded a quake that was the largest to hit the San Francisco Bay Area since the devastating 6.9-magnitude Loma Prieta earthquake 25 years ago in 1989.

ShakeAlert is not a predictive tool — predicting quakes is still beyond the expertise of even the most eminent seismologists; rather it is being developed to act as an early-warning system to help minimize quake damage. For example, with even a little warning, BART trains could slow down to avoid derailment, utilities companies could shut off gas vales to prevent fires, elevators could be stopped and their doors opened at a floor, and surgeons could stop operating. … Continue reading »

UPDATE 4:07 pm: Genie Stowers, the professor who sent out the original email issued an apology this afternoon by email. Here it is:

Last week, I sent out an email to family and close friends and colleagues about recent earthquakes.

My intent was to pass on a message that they should take the occurrence of these recent earthquakes as an opportunity to make sure their earthquake kits and other emergency measures were up to date.

It is unfortunate that this email instead went viral and has caused great concern among many in the Berkeley area.

My message was not intended to be a commentary on earthquake science, on City of Berkeley preparedness, or on anything else except that folks should get ready. The message was intended to be, preparedness is good.

I apologize for what has happened and the concerns this caused. It was a mistake and I regret that it happened. … Continue reading »

What can you tell us about the recent quakes centered in Berkeley?The magnitude 4:0 quake [which was felt at 2:41 pm on Thursday October 20] was followed by several aftershocks in the area of rupture over the next few days as the earth tried to come back into equilibrium. Aftershocks are defined as being smaller than the original quake.

Some Berkeleyside readers said they thought a series of small quakes was a good thing because it indicated a “release of pressure” on the Hayward fault line; others said it indicated a “build-up to a big one”. Are either of these ideas valid?Both are legitimate theories. The truth is we don’t know whether earthquakes like these are relieving pressure or whether pressure is building. … Continue reading »